CN103169498B

CN103169498B - Mother during heart of fetus monitors contributes detection

Info

Publication number: CN103169498B
Application number: CN201210557780.0A
Authority: CN
Inventors: S.卡巴科夫; S.M.法尔克; B.C.富克斯
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 2011-12-20
Filing date: 2012-12-20
Publication date: 2017-12-29
Anticipated expiration: 2032-12-20
Also published as: US8617076B2; US20130158407A1; CN103169498A

Abstract

The present invention's is entitled：" mother during heart of fetus monitors contributes detection ".Contributed by suppressing any mother from ultrasonic signal to determine that fetal cardiac signals are contributed according to ultrasonic signal.Fetal cardiac signals contribution is eliminated or subtracted from ultrasonic signal.Result based on elimination, export alarm.

Description

Mother during heart of fetus monitors contributes detection

The cross reference of related application

The application is related to Serguei Kabakov, Steven M.Falk and Bradley Fox on December 20th, 2011 The sequence of CO-PENDING submit, entitled " FETAL HEART MONITORING RANGE (heart of fetus monitoring range) " Number be No.13/331,197 (lawyer Reference Number No.254759) U.S. Patent application, the entire disclosure of this application by reference and It is incorporated herein.

Technical field

The present invention relates to a kind of heart of fetus monitoring method, a kind of heart of fetus monitoring system and a kind of medical apparatus.

Background technology

Heart of fetus monitoring measures the physiologic parameters of the heart of unborn child using ultrasonic transducer.At some In situation, stomach fat can increase distance between ultrasonic transducer and monitored heart of fetus.Increase ultrasonic pulse penetrates Depth can reduce signal noise ratio to adapt to this larger distance, and can undesirably result in ultrasonic transducer from mother The signal outside the signal from fetal heart frequency is picked up in belly vascular or substitutes the signal of the signal from fetal heart frequency.

The content of the invention

The present invention provides a kind of method, including：The ultrasonic signal from heart of fetus is obtained from ultrasonic transducer；Pass through suppression Any mother from ultrasound echo signal is made to contribute to determine the fetal cardiac signals contribution to the ultrasonic signal, wherein, Fetal cardiac signals contribution is the component of the ultrasonic Doppler echo-signal as caused by the pulsation of heart of fetus, and wherein, it is female Parent's contribution is the component of the ultrasonic Doppler echo-signal as caused by the pulsation of the blood in mother's abdominal muscles；From ultrasonic signal The fetal cardiac signals contribution is eliminated, wherein, based on the result of the elimination, export alarm.

On the other hand, there is provided a kind of heart of fetus monitoring system, including：Ultrasonic transducer；Controller, it is configured to produce The raw operation for guiding the ultrasonic transducer and the control signal for receiving the echo-signal from the ultrasonic transducer, it is described Controller is configured to：The ultrasonic signal from heart of fetus is obtained from ultrasonic transducer；And by suppressing to come from ultrasonic signal Any mother contribute to determine to the contribution of the fetal cardiac signals of ultrasonic signal, wherein, fetal cardiac signals contribution is by tire The component of ultrasonic Doppler echo-signal caused by the pulsation of youngster's heart, and wherein, mother's contribution is by mother's abdominal muscles In blood pulsation caused by ultrasonic Doppler echo-signal component；And the heart of fetus letter is eliminated from ultrasonic signal Number contribution, wherein, the result based on elimination, export alarm.

On the other hand, there is provided a kind of medical apparatus, including：For being obtained from ultrasonic transducer from heart of fetus The device of ultrasonic signal；For being contributed by suppressing any mother from ultrasonic signal, it is determined that the tire to the ultrasonic signal The device of youngster's heart signal contribution, wherein, fetal cardiac signals contribution is the ultrasonic Doppler as caused by the pulsation of heart of fetus The component of echo-signal, and wherein, mother's contribution is the ultrasonic Doppler as caused by the pulsation of the blood in mother's abdominal muscles The component of echo-signal；And for eliminating the device of the fetal cardiac signals contribution from ultrasonic signal；And for base In the result of the elimination, the device of alarm is exported.

Brief description of the drawings

Fig. 1 schematically shows an example of heart of fetus monitoring system；

Fig. 2 is the flow chart for showing the exemplary method for the heart of fetus monitoring system execution by Fig. 1；

Fig. 3 is to show the figure for identifying the exemplary method of heart of fetus window using the signal from transducer Show；

Fig. 4 is to show the flow for identifying the exemplary method of heart of fetus window using the signal from transducer Figure；

Fig. 5 is the flow chart for showing the existing example removing method for identifying mother's signal；

Fig. 6 is the data flowchart for showing the example data flow during Fig. 5 method；

Fig. 7 is for using identifying the associative mode of the influence of mother's signal to carry out the example of heart of fetus monitoring The control flow chart of method；

Fig. 8 is the example implementation of the heart of fetus monitoring system for the Fig. 1 for schematically showing the method for performing Fig. 7 Diagram；

Fig. 9 is the control flow chart of the exemplary method for the scanning for identifying heart of fetus window；

Fig. 9 A are to show alternately to send and receive ultrasonic signal on different passages in different belly depths Example timing diagram；

Figure 10 is those structures for the heart of fetus monitoring system for schematically showing the Fig. 8 used during associative mode The diagram of part；

Figure 10 A are to show the ultrasonic signal sent and received during heart of fetus monitors on heart of fetus window Example timing diagram；

Figure 11 be for using elimination pattern with identify mother's signal influence come carry out heart of fetus monitoring another The control flow chart of exemplary method；

Figure 12 is those structures for the heart of fetus monitoring system for schematically showing the Fig. 8 used during elimination pattern The diagram of part；

Figure 13 is the flow chart for identifying the exemplary method of the influence of mother's signal.

Embodiment

Fig. 1 schematically shows example heart of fetus monitoring system 20.As will be described hereinafter, the fetus heart Dirty monitoring system 20 limits window around heart of fetus, and the window is used subsequently to the heart of fetus monitoring concentrated.Changed in ultrasound During energy device is monitored to heart of fetus, heart of fetus monitoring system 20 is determined using benchmark fetal cardiac signals Whether the signal received from ultrasonic transducer is received through the influence of the pulsation of the blood flow of mother's belly vascular.Therefore, signal is made an uproar Acoustic ratio is maintained, and the reliability enhancing of heart of fetus monitoring.

Heart of fetus monitoring system 20 includes ultrasonic transducer 24, strip recorder 26, display 28, loudspeaker 30, place Manage device 32 and memory 34.Ultrasonic transducer 24 (schematically showing) includes one or more ultrasonic transducers, each transducing Device includes transmitter and receiver.Each transducer 24 is configured to install or is supported on that (its receiving is unborn close to uterus 40 Child 42) belly 38 near.In one embodiment, it is possible to provide a part of the ultrasonic transducer as ultrasonic detector.Respectively Individual transducer 24 is configured to produce the ultrasonic wave or supersonic beam for pointing to unborn child or fetus 42, wherein, ripple or beam are from tire Youngster 42 is reflected, and bounces back into transducer 24.Due to moving heart, the ultrasonic echo or ultrasonic signal of return carry by The information that Doppler frequency shift obtains.Information included in such back wave or beam is used for determining fetus 42 by processor 32 Heart rate.

Strip recorder 26, display 28 and loudspeaker 30 (can serve as alarm) are included visually or audibly to nursing staff The notice mechanism of output information.Strip recorder 26 includes being configured to print determining based on the signal received from transducer 24 The device of physiologic parameters (such as heart rate).Display 28 includes monitor, screen, or heart rate information is in visually by it Now give other devices of nursing staff.Loudspeaker 30 includes being configured to export the audible information (heart such as detected by transducer 24 Jump sound) device.In one implementation, loudspeaker 30 and/or display 28, which can be used to provide, audible or visual notify, is alert Announcement or alarm, it is necessary the heart rate characteristic worried or the characteristic sensed so as to remind nursing staff to pay attention to.In some implementations, tire Youngster's cardiac monitoring systems 20 can omit one or more of such output device 26,28 and 30, or may include extra Or alternative output device.

Processor 32 includes one or more processing units, and processing unit is configured to：Produce guiding and use transducer 24 Transmitting and the control signal for receiving ultrasonic signal, to handle and analyze the signal received from transducer 24；And based on this point The result of analysis and the control signal for producing output of the guiding to one or more of output device 26,28 and 30.In some realities In existing, such signal can be stored in memory 34 by processor 32 in addition, to be analyzed afterwards, and will can be analyzed As a result it is stored in memory 34.For the purpose of the application, term " processing unit " should represent exploitation at present or develop in the future , perform be included in memory 34 in command sequence processing unit the meaning.Execute instruction sequence can hold processing unit Row such as produces the step of control signal.Instruction can from read-only storage (ROM), mass storage device or some it is other persistently Storage is loaded into random access memory (RAM), to be performed by processing unit.In other embodiments, hardwire electricity can be used Road replaces software instruction, or can be used in combination with hard-wired circuitry and software instruction, to realize described function.Example Such as, a part for processor 30 and memory 34 can be presented as one of one or more application-specific ICs (ASIC) Point.Unless otherwise indicated, processor 32 is not limited to any particular combination of hardware circuit and software, is also not necessarily limited to by processing unit Any specific source of the instruction of execution.

Memory 34 includes storage transducer location search module 50, heart of fetus window identification module 52, heart of fetus Monitoring modular 54, signal quality comparison module 56, pattern comparison module 58, eliminate comparison module 60 and data division 62 it is non-temporarily The computer-readable medium of when property.Although memory 34 is shown as into single memory structure, in other realizations, data division 62 different module or different parts are storable at different memory locations.For example, it is stored in memory 34 Some projects are storable in local, and other projects are storable at a distance, can pass through network access.

Module 50,52,54,56,58 and 60 each includes being stored in memory 34 and being configured to bootstrap processor 32 holding The process or the computer-readable program or code of the non-transitory of method 100 shown in row Fig. 2.As indicated as step 102 Like that, the processor 32 of the instruction included in transducer location search module 50 is deferred to during transducer position search pattern Guiding or instruction processor 32.During this pattern, transducer 24 moves past belly 38 by nursing staff, while launches and receive super Acoustical signal, to identify generation reflection of the transducer 24 on belly 38 from the position of the peak signal of the heart of fetus 22.One In individual realization, during transducer positions search pattern, as transducer 24 is manually repositioned at belly 38 by nursing staff On diverse location at, processor 32 guides transducer 24 interior in the four corner (nominally be 3cm to 30cm) of transducer 24 Send and receive supersonic beam.The bootable display 28 of processor 32 or strip recorder 26 provide the ultrasound received by transducer 24 The visual representation of signal.Processor 32 can further amplify ultrasonic signal, and produce and treat to be corresponded to by what loudspeaker 30 exported The audible output of heartbeat.Therefore, audible output can be used to identify position of the transducer 24 on belly 28, in this position in nursing staff Put, the output from loudspeaker 30 is the characteristic of heart of fetus bounce, and is most strong or most loud.

As indicated as the step 104 in Fig. 2, once transducer 24 has been properly positioned on belly 38, defer to The processor 32 of instruction included in heart of fetus FH windows identification module 52 identifies and limited the heart comprising fetus 42 Window or volume.In identification window, processor 32 determines ultrasonic transducer 24 and fetus using the ultrasonic signal received Approximate distance between heart.Based on this approximate distance, the identification of processor 32 comprising heart of fetus and including with transducer 24 Minimum and maximum distance scope or window.In one implementation, processor 32 limits scope or window so that this scope Or the predetermined distance of estimation circumferential, spaced-apart on the border and heart of fetus of window.Therefore, no matter how fetus 22 moves, or No matter how mother moves person, and the possibility that heart of fetus will remain in identification range or window improves.

In one implementation, the estimation circumferential, spaced-apart at least 3cm of the border of this scope and heart of fetus.In a realization In, scope has the wide cores of 3cm, this be more than 1 to 2cm sizes heart of fetus, and each side from core 3cm is buffered.In other examples, distance that scope or window can be different from the circumferential, spaced-apart of heart of fetus.

In other examples, scope may include the only one in minimum range or ultimate range with transducer 24.One In individual realization, window is two-dimentional, and it is included in sagittal plane.In another realization, the window that is limited by processor 32 Can be three-dimensional, so as to limit a volume around heart of fetus.

Fig. 3 and 4 shows that the processor 32 for deferring to the instruction provided by module 52 can be used to identify heart of fetus window A kind of method.Fig. 3 shows the transducer for being positioned against belly 38 and being positioned to sense the fetal heart frequency of heart of fetus 150 24.Fig. 4 is the flow chart for identifying the method 200 of the window 152 (figure 3 illustrates) around heart of fetus 150.

As indicated as the step 202 in Fig. 4, when being run in scan pattern, defer to what is provided by module 52 The processor 32 of instruction produces the control signal for making transducer sense overlapping belly depth area 156 (being designated as A-H in figure 3).Tool For body, processor 32 produces the control for making transducer transmitting supersonic beam and receiving the ultrasonic signal reflected at each depth area Signal.In one example, processor 32 makes the transmission signal of transducer 24 and received from following overlapping 6cm depth area Signal：3-9cm, 6-12cm, 9-15cm, 12-18cm, 15-21cm, 18-24cm, 21-27cm and 24-30cm.In other realizations In, the degree that the width in each overlapping depth area and such area overlap each other can have other values, or can be with area not Change together.For example, at estimated the be located at distance of heart of fetus, such area can have the lesser width (starting point in area The distance between terminal), so as to cause the density in the area in the estimated region comprising heart of fetus larger.In a realization In, the distribution in area may be selected in tender, so as to influence the density in the area away from transducer 24.Therefore, can improve in heart of fetus The accuracy of 150 identified opening positions.

In one implementation, processor 32 guides the gamut that the scanning of transducer 24 passes through belly depth area 156.Another During one is realized, processor 32 prompts the estimating depth that tender inputs (being inputted by user) heart of fetus 150 (with transducer 24 distance), either on other physiological informations (weight of mother, height etc.) of mother or on fetus Information (age of fetus, weight, orientation etc.), or the information on the stage of being born, wherein, processor 32 uses this Information estimates the position of heart of fetus 150.Based on the estimated location of heart of fetus 150, processor 32 eliminates alert area 156, So as to only scan those areas 156 for more likely including heart of fetus 150.Therefore, the position of heart of fetus 150 can be positioned more quickly Put.

After ultrasonic signal is received from the transducer 24 in each area 156, two are evaluated or measured to processor 32 Characteristic：The intensity of ultrasonic signal from specific area, and the heart rate from specific area and detecting from one group of area Heart rate between the degree of consistency.In one implementation, processor 32 produce cause transducer 24 sense it is each individually Area while or almost simultaneously, launch and receive the control letter of supersonic beam in multiple areas 156 or in all areas 156 Number.For example, in being realized using one of single transducer 24, processor 32 can alternately be sensed using single transducer 24 (A) individually area 156 is (more using the time-division by all areas 156 or whole abdomen area (in the above examples, 3cm-30cm) and (B) (TDMA) is accessed in location).In this realization, processor 32 also evaluate heart rate in single area 156 with from one group of area or whole The uniformity or degree that meet or match of the heart rate sensed in abdomen area (in the above examples, 3cm-30cm).

As indicated as the step 204 in Fig. 4, signal intensity and the heart from each area 156 are being sensed and collected After rate uniformity, a pair of adjacent regions 156 of the identification of processor 32 with strongest signal strength and highest heart rate uniformity.Example Such as, in some cases, two groups of adjacent regions can show stronger ultrasonic signal.In this case, processor 32 is comparing The heart rate of the signal of each middle appearance in two groups of adjacent regions with received from gamut (in the above examples, 3cm to 30cm) Ultrasonic signal heart rate.Heart rate consistent degree highest ultrasound with the heart rate with the echo-signal from gamut is returned A pair of adjacent regions of ripple signal are identified as the basic one group adjacent region that should be used as window 152 by processor 32.

As indicated as the step 206 in Fig. 3, processor 32 using two adjacent regions of selection apart from border come Limit heart of fetus window 152.In one implementation, the lap of two adjacent regions is identified as window 152 by processor 32 Core.Exactly in this core of window, whole heart of fetus must be included.For example, if there is highest The area of intensity and heart rate consistent degree is area 9-15cm and 12-18cm, then the lap in such area appears in 12cm extremely 15cm depth.It is being that this lap must include heart of fetus.

By using this information, processor 32 and then formation include interval or the window buffered.Processor 32 is by window 152 be defined be added/subtracted from from the lap of adjacent region limit in advance with a distance from proximal border and distal border (relative to Transducer 24).In the illustrated example, the proximal border of two overlay regions and distal border are used as in window 152 by processor 32 Border and external boundary, so as to provide window 152 interval or buffering in the either side of the lap in area.For example, based on 9 to The window of 15cm and 12 to 18cm overlay region by proximal border and 18cm distal border with 9cm, wherein, heart of fetus is located at In 12 to 15cm lap.Once limiting, the position of heart of fetus 150 and the border of window 152 are just deposited by processor 32 In the window's position (WL) part 66 for storing up the data storage section 62 in memory 34.In other realizations, other distances or It is other to buffer the inner boundary and external boundary that can be used to establish window 152.

Although method 200 identifies adjacent region, and limits heart of fetus window based on signal intensity and heart rate uniformity 152, in other realizations, it can be identified using the only one in these factors with the basic adjacent region for being construed as limiting window 152 156.In other realizations, extra sensing factor or input criterion can be used to identify the basic phase for limiting window 152 Adjacent area 156.In other other realizations, such as, wherein, area's density in a region is higher (width in area is smaller), place Reason device 32 can be estimated the position of heart of fetus 150 and be limited window 152 using many more than two area.

After window 152 is limited, as indicated as the step 106 in Fig. 2, processor 32 prompts tender to carry out One in two available mother's pulse (MP) recognition modes 108 and 110 of input or selection.As will be described, Pattern 108 periodically compares between the benchmark pattern of the monitoring pattern of ultrasound echo signal and the initial storage of ultrasound echo signal Degree of correlation, to identify the presence of mother's pulse or influence.In one implementation, the benchmark of the ultrasound echo signal of storage is compared The frequency spectrum of frequency spectrum and monitoring ultrasound echo signal.

On the contrary, pattern 110 from combined monitoring signal in a manner of mathematics eliminating fetal cardiac signals, it is first to determine The presence for any mother's pulse begun in the window 152 of positioning.If it is determined that remaining signal includes mother's arteries and veins after cancellation Punching, then notify tender, and reposition transducer.In one implementation, this process is repeated, until no longer in window Untill the presence that mother's pulse is detected in 152.Once transducer 24 is located so that window 152 does not show mother's pulse, then Monitoring continues, and accident below tries contribution of the mother to signal, because the sustainer of mother is moved unlike heart of fetus Influence.But due to fetus it is mobile and caused by poor or weak signal, transducer 24 can be repositioned.Transducer 24 this It is rational that kind, which repositions the new heart of fetus window 152 of provable identification, and the method for execution pattern 110 again, To ensure that new heart of fetus window will not cover mother's belly vascular, mother's belly vascular and abdominal aortic are in a row, and And influence ultrasonic experiments.In other realizations, heart of fetus monitoring system 20 can provide associative mode 108 and elimination pattern 110 Only one in the two.

As indicated as step 112, if selected for pattern 108, then processor 32 stores the window received from selection The initial pattern of the referenced ultrasound echo-signal of mouth 152.In one implementation, pattern (that is, the benchmark of referenced ultrasound echo-signal Pattern) be stored in by processor 32 memory 34 data storage section 62 benchmark pattern RP storage part 68 in (in Fig. 1 Show).As indicated as step 114, once storing the pattern of referenced ultrasound echo-signal, defer to and supervised by heart of fetus The fetus heart concentrated and shown in figure 3 is launched and received to the generation guiding transducer 24 of processor 32 for surveying the instruction that module 54 provides The control signal of ultrasonic signal at dirty window 152.

As indicated as step 116, the ultrasound that the expression reflection from transducer 24 is received with processor 32 is believed Number signal (" monitoring signals " S), the base for passing through the pattern for comparing monitoring signals and being stored in benchmark pattern storage part point 68 The pattern RS of calibration signal, the processor 32 for deferring to the instruction included in pattern comparison module 58 evaluate the pattern of monitoring signals. If the pattern of monitoring signals is fully related to the pattern of reference signal, alarm is not exported, and continues to monitor heart of fetus Window 152.But as indicated as step 118, if the pattern of monitoring signals is deficiently corresponding with reference signal Pattern it is related, then processor 32 determines that at least a portion of the signal received from transducer 24 can be that the sensing of transducer 24 pass through The result of the blood flow (mother's pulse) of mother's belly vascular.Therefore, processor 32, which produces, causes by using output 26,28 and 30 In at least one control signal that alarm is presented to tender.In one implementation, loudspeaker 30 is in response to from processing Such control signal of device 32 and produce audible alarm, so as to indicate wherein received from transducer 24, be shown in display 28 The situation that ultrasonic signal that is upper and being imprinted by strip recorder 26 can be influenceed by mother's belly vascular at least in part.By this After kind situation is reminded, tender can take remedial action, such as reposition or adjust position or the transducer of transducer 24 The belly depth of 24 sensings.Tender also may check that the situation or health (figure 1 illustrates) of fetus 42.

In one implementation, in order to determine whether the pattern of monitoring signals fully corresponds to the pattern of reference signal, locate In the dependent thresholds TH parts 70 (figure 1 illustrates) of the evaluation of reason device 32 and the data storage section 62 for being stored in memory 34 The comparison of the matching threshold limited in advance.Threshold value tool selectively value so that threshold value it is sufficiently low and even if monitoring ultrasonic echo Signal is merely due to heart of fetus angular orientation changes and changes and be also exceeded, so as to avoid false alarm.Meanwhile threshold value has Sufficiently high value, to monitor ultrasound echo signal because fetal stress deteriorates or due to making transducer 24 undesirably lock It is not exceeded when the influence that mother on unnecessary mother's belly vascular or fetus move changes.

In one example, the average amplitude spectrum of fetal heartbeat is used as the pattern of reference signal, benchmark signal The average amplitude of pattern and monitoring signals is composed.In one implementation, coefficient correlation is used as the pattern of monitoring signals and benchmark is believed Number pattern between similitude measurement.In one example, with every the interval of 10 seconds with 2ksps sampling rate from prison Survey in signal and obtain average amplitude spectrum.Coefficient correlation is that the Pearson (Pearson) between reference signal and monitoring signals is related Coefficient.If coefficient is less than threshold value, tender is notified or presented instruction and loses fetal cardiac signals and may be locked in Alarm on mother's belly vascular.In other examples, other patterns, other sampling rates and other coefficient correlations can be used Make the correlation between reference signal and monitoring signals or matching.

As indicated as step 119, if selected for pattern 110 is eliminated, defer to by heart of fetus monitoring modular 54 The processor 32 of the instruction of offer produces guiding transducer 24 and launches and receive the heart of fetus window concentrated and shown in fig. 2 The control signal of ultrasonic signal on 152.In one implementation, the sample of ultrasound echo signal is received in the period limited in advance This.In one implementation, ultrasound echo signal is received in the 10 seconds periods limited in advance.Then in step 120-126, abide by From included in the processor 32 for eliminating the instruction in comparison module 60 mother is determined using this sample of ultrasound echo signal Presence of the pulse in heart of fetus window 152.

As indicated as step 120, processor 32 identifies that the sample received during the period limited in advance surpasses The fetal signals part M (fetal cardiac signals contribution) of sound echo-signal.Fetal cardiac signals contribution is due to heart of fetus The component of ultrasonic Doppler echo-signal caused by pulsation.As indicated as step 122, processor 32 is then from compound The fetal signals part M of identification is subtracted in monitoring ultrasound echo signal.Then ultrasound echo signal S1 remainder is by handling Device 32 be used for determine in the case where transducer 24 is positioned on belly 38 at present (figure 1 illustrates), in window 152 whether Detect mother's pulse (mother contributes, if any).Mother's contribution be due to the pulsation of blood in mother's abdominal muscles and The component of caused ultrasonic Doppler echo-signal.

As indicated as step 124, defer to and evaluated included in the processor 32 for eliminating the instruction in comparison module 60 Remaining or remaining signal or value S1.If there is no remaining quasi-periodic signal S1, then alarm is not provided, such as by step As 125 instructions so that can start continuously to monitor heart of fetus.Alternatively, as indicated as step 126, if Remaining quasi-periodic signal S1 be present, then processor 32 compare the heart rate HR1 that obtains or detect on residual signal S1 with just Beginning heart rate HR (before elimination, calculated according to combined monitoring ultrasound echo signal heart rate), to determine residual signal S1 Heart rate it is whether consistent with initial heart rate HR (that is, the heart rate obtained in combined monitoring echo-signal).If residual signal S1 Heart rate HR1 it is consistent with initial heart rate HR, then alarm is not provided, as indicated as step 127 so that can start continuously Monitor heart of fetus.

But as indicated as step 128, if residual signal S1 heart rate HR1 be unsatisfactory for predefine with just The degree or threshold value of beginning heart rate HR uniformity, then processor 32 determine that at least a portion of the signal received from transducer 24 is The result for the blood flow (mother's pulse) that the sensing of transducer 24 passes through mother's belly vascular.Therefore, processor 32 produces and causes to use At least one control signal that alarm is presented to tender in output 26,28 and 30.In one implementation, the sound of loudspeaker 30 Ying Yu produces audible alarm from such control signal of processor 32, so as to indicate wherein received from transducer 24, show Show what the ultrasonic signal imprinted on the display 28 and by strip recorder 26 can be influenceed by mother's belly vascular at least in part Situation.After being reminded by this situation, tender can take remedial action, such as reposition or adjust transducer 24 The belly depth that position or transducer 24 sense.Tender also may check that the situation or health (figure 1 illustrates) of fetus 42.

Fig. 5 shows method 300, i.e. an example implementation of pattern 110.Fig. 6 shows a number of examples of method 300 According to flow chart.As mentioned above, according to step 119, in one implementation, sample ultrasound was received in 10 second cycle and is returned Ripple signal S.Figure 6 illustrates the EXAMPLES Ultrasonic echo-signal S 350 for being derived from window 152 (figure 3 illustrates).Such as by Fig. 6 As showing, signal S 350 includes multiple fetal heartbeat groups 352, and each group 352 includes the first bounce 1 and the second bounce 2.Sample This signal S 350 can further comprise mother's signal 3.

Step 302-312 be used for by suppress any mother from original or unprocessed signal S 350 contribute come Identify the fetal signals part M from composite ultraphonic echo-signal 350.As indicated as step 302, processor 32 is to letter Number S 350 performs auto-correlation, to produce the heart of fetus shown in Fig. 6 bounce peak value 356 (being based on the first fetal heartbeat).Such as by Step 304 instruction as, processor 32 determine or obtain as heart of fetus beat peak value between cycle.Such as by Fig. 6 As showing, the distance between adjacent peak 356 composition cycle H P [n], wherein, n=1 ... N.Such as by the step 306 in Fig. 5 As instruction, by using the cycle of calculating, processor 32 identifies minimum fetal heartbeat cycle H Pmin.Such as by the step in Fig. 5 As rapid 308 instruction, section that processor 32 is come in shutoff signal S 350 using the HPmin of this determination.Show what is shown In example, such section has HPmin length, and with the first fetal heartbeat (FHB of each group heartbeat 352₁) consistent.Scheming Example composite signal section S [n], wherein n=1 ... N are shown in 6.

As indicated as step 310, for starting and having the HPmin duration at autocorrelation peak 356 Each composite signal section S [n], processor 32 is by by first of the fetal signals in section divided by associated section S [n] The amplitude A [n] of bounce makes section standardize, as shown as Stream Element 362.Such as indicated by step 312 and Fig. 6 In frame 364 indicate as, processor 32 determine normalization section signal S [n] average value, wherein n=1 ... N.This is flat Average forms the Standardized Model M (fetal cardiac signals contribution) of fetal signals.

As indicated as step 314, in order to determine mother's signal contribution, then from original undressed signal S Fetal cardiac signals contribution (model M) is eliminated, wherein, this result eliminated is used for determining whether that alarm should be exported.Showing In the example gone out, as indicated as step 314, processor 32 is subtracted from each compound section S [n] and standardized (denormalized) model M, to identify residual signal S1 [n].Specifically, as the data flow line 366 shown in Fig. 6 that Sample, for each section S [n], mould is multiplied by with the amplitude A [n] of the first bounce of the fetal signals in associated section S [n] Type M makes the model M go to standardize.Figure 6 illustrates example in, such subtraction can make mother's pulse signal 3 (in figure 6 Line 366 on) be likely to be present in residual signal S1 [n] 366.

As indicated as step 316, heart rate HR (it be fetal heart frequency) and letter of the processor 32 also on detection signal S Heart rate HR1 on number S1, signal S1 are the composite signals after fetal signals elimination.Fetal heart frequency HR such as formula HR [n]= As 60000/HP [n] (n=1 ... N) restrictions in units of bounce per minute, wherein, HP [n] is the phase on Fig. 6 line 356 Distance between the peak value of pass, in units of microsecond.Remaining signal S1 heart rate HR1 is by HR1 after fetal signals elimination [i]=60000/HP1 [i], i=1 ... I limit, wherein, HP [i] be the S1 shown on Fig. 6 line 366 auto-correlation function (not Display) correlation peak between, distance in units of millisecond.

As indicated as step 318, processor 32 determine residual signal S1 any heart rate HR1 this subtraction it After whether there is.If there is no residual signal S1 heart rate HR1, then alarm is not provided as step 320 indicates.Alternatively Ground, if there is residual signal S1 heart rate HR1, then processor 32 determine residual signal heart rate HR1 whether with signal S The fetal heart frequency HR of acquisition is consistent.As indicated as step 322, if residual signal S1 heart rate HR1 satisfactions are true in advance The fetal heart frequency HR with fetal signals limited calmly or in advance consistent degree, then do not provide police as step 324 indicates Report.Alternatively, if residual signal S1 heart rate HR1 and fetal heart frequency HR are inconsistent, processor 32 is as step 320 indicates Produce alarm like that.In one implementation, predetermined consistent degree is established by the threshold value of 5 times per minute bounces, wherein, If HR1 and HR difference exceedes this threshold value, alarm is exported in step 324.In other realizations, using other pre- The consistent degree first determined or other threshold values.

As mentioned above, processor 32, which produces, causes at least one to compare using export in 26,28 and 30 The control signal of alarm is presented in pipe person.In one implementation, loudspeaker 30 is believed in response to such control from processor 32 Number and produce audible alarm, so as to indicate wherein received from transducer 24, shown on the display 28 and by strip recorder The situation that the ultrasonic signal of 26 impressings can be influenceed by mother's belly vascular at least in part.After being reminded by this situation, Tender can take remedial action, such as reposition or adjust the position of transducer 24 or the belly depth of the sensing of transducer 24 Degree.Once transducer has been repositioned, so that it may performs method 300 again.Repeat this process, until it is such again Untill positioning will not provide alarm, it is located so that window 152 not by any mother so as to indicate transducer 24 on belly 38 Pulsing effect.At this point, the normal continuous monitoring of fetal heart frequency can be performed by heart of fetus monitoring system 20.

Fig. 7 is the control flow chart for showing the exemplary method 400 for monitoring single fetus.Fig. 8 is schematically to show Go out each several part of example heart of fetus monitoring system 520, can be used to perform the heart of fetus monitoring of each several part of method 400 The block diagram of one realization of system 20.Fig. 8 show system 520, for limiting or identify heart of fetus window (such as Fig. 3 In the heart of fetus window 152 that shows) those components.Fig. 8 further illustrate system 520, for initially by transducing Device 24 is positioned at the component on belly 38.As shown as Fig. 8, heart of fetus monitoring system 520 includes the He of transducer 524 Simulate component：Digital Logic 526, send signal amplifier 528, receive echo amplifier and narrow band filter 530 (such as about 1MHz centre frequency), demodulator 532, heart of fetus monitoring system 520 receive strobe switch 534, sampling and keep electricity Container 1 and 2 (536), bandpass filter 1 and 2 (538), multiplexer 540, amplifier 542, loudspeaker 544, automatic gain Controller 1 and 2 (546), envelope detector 1 and 2 (548) and analog-digital converter 550.In other realizations, such simulation structure Part can be provided alternatively by numeric components, or be realized in software in the processor.

As further shown as Fig. 8, heart of fetus monitoring system 520 is additionally included in the rear end system realized in software System.Such backend component includes fetal heart frequency detector 1 and 2 (554), display 556, strip chart recording instrument or printer 557th, signal-quality detector 1 and 2 (558), signal quality comparator 560, heartbeat consistency detector 562, window choosing Select device (also referred to as timing diagram (TD) selector) 564, memory 566, heart of fetus pattern detector 568, keyboard 570 and scanning Scheduler 572.

As illustrated as Fig. 7 control flow, transducer 524 (figure 8 illustrates) is initially positioned at mother's belly Surface on.As shown in Figure 7 like that, tender (operator or nurse) opens heart of fetus monitoring system 520, and leads to Cross keyboard 570 (figure 8 illustrates) and order is inputted to scan schedule device 572, to enter transducer position search pattern.In response to This order, Digital Logic 526 (including field programmable gate array (FPGA), complicated programmable logic device (CPLD) or Processor) ultrasound transmission tone signal (tone signal) TRANS (nominally characteristic frequency with about 1MHz) is produced, Ultrasound sends the exaggerated devices 528 of tone signal TRANS and amplified, and is guided to fetus 42 and (show in Fig. 1 by transducer 524 Go out).In the illustrated example, during this search pattern, transducer 524 is repositioned in tender to pass through loudspeaker 544 see or listen with heart of fetus bounce characteristic most strong echo-signal when, transducer 524 sense 3cm to 30cm it is whole Scope.

Corresponding to the frequency with the speed shunk corresponding to heart of fetus reflected impulse echo-signal by transducer 524 receive, and are amplified by reception echo amplifier 530.After being exaggerated, echo-signal is subjected to signal transacting.Showing Realization in, signal is demodulated device 532 and demodulated, and is transmitted through passage 1, including：Sampling and holding capacitor device --- keep 1 (HOLD 1) 536, bandpass filter 538 (wave filter 1), automatic growth control AGC1 546 and envelope detector ED1 548. In the example shown, each bandpass filter 1 and 2 (538) filters out the signal with the frequency less than 100Hz and 300Hz, with Remove extraneous signal.As indicated as arrow 576, the signal of wave filter 1 is sent to multiplexer 540, and is put Big device 542 amplifies, to obtain audible output by loudspeaker 544.

As the further instruction of arrow 578, the signal of wave filter 1 further passes through automatic gain controller 1 (546), automatic gain controller 1 (546) provide such signal stable amplitude, so as to eliminate and heart of fetus and change The changeability that different distance between energy device 524 is associated.In the envelope inspection of such signal experience envelope detector 1 (548) After survey, such signal is sent to analog-digital converter 550, to enter the back-end digital structure of behavior heart of fetus monitoring system 520 The numeral conversion that part part uses.As mentioned above, in some implementations, so simulation component mainly replaces digital structure Part part.

In transducer positions search pattern, utilize only one passage (passage 1).Signal from analog-digital converter is sent To fetal heart frequency detector 1 (554), fetal heart frequency detector 1 (554) identification fetal heart frequency, and it will estimate that fetal heart frequency is defeated Go out to display 556 and strip recorder 557.By mainly using audible output and display 556 from loudspeaker 544 Or transducer 24 constantly can be repositioned on belly 38 by the visual output in any one in printer 557, tender, Until being heard on loudspeaker 544 and/or seeing fetal heartbeat in the output of display 556 and/or printer 557 Untill peak signal characteristic.Once transducer 544 is positioned on belly by tender in initial monitor opening position, tender The order for leaving transducer position search pattern is just inputted by keyboard 570.Therefore, or it is automatically, or in response to by looking after The order that person is inputted using keyboard 570, scan schedule device 572 make the startup of monitoring system 520 scan pattern SM (show in the figure 7 Go out).

In scan pattern SM, method 200 (figure 4 illustrates) is performed.Fig. 9 is the system that shows 520 in scan pattern The control flow chart of the operation of period and associated table.As indicated as the line 660 and 662 in Fig. 9, in specific tire In youngster's cardiac monitoring systems example 520, Digital Logic 526 produce ultrasound send tone signal TRANS (nominally with about 1MHz carrier frequency), ultrasound sends the exaggerated devices 528 of tone signal TRANS and amplified, and is guided by transducer 524 to tire Youngster 42 (figure 1 illustrates).In the illustrated example, during this scan pattern, Digital Logic 526 produces ultrasound and sends list Sound signal, ultrasound send the exaggerated device 528 of tone signal and amplified so that transducer 524 alternatively launches ultrasonic signal, Yi Jijie Receive the gamut (line 660 in Fig. 9) from (A) 3cm to 30cm and the ultrasound in (B) each depth area (line 662 in Fig. 9) Echo-signal.

In one example, Digital Logic 526 makes (time division multiple acess accesses (the TDMA)) hair in an alternating fashion of transducer 524 Ultrasonic signal is penetrated, and receives the echo letter in 6cm depth area overlapping below gamut and (B) from (A) 3cm to 30cm Number：3-9cm, 6-12cm, 9-15cm, 12-18cm, 15-21cm, 18-24cm, 21-27cm and 24-30cm so that from whole Scope 3-30cm echo-signal is processed in passage 1 (keeping 1 to wave filter 1 to AGC 1 to ED 1), is simultaneously from current The echo-signal in depth area is processed in passage 2 (keeping 2 to wave filter 2 to AGC2 to ED 2).

Fig. 9 A be an example for showing this alternate ultrasonic penetration range scans timing diagram and it is associated when Sequence table.As shown as Fig. 9, Digital Logic 526 and amplifier 528 make transmission tone signal 600 be sent out by transducer 524 Penetrate, wherein, the tone signal 600 that sends of this transmitting is being oriented to the single-tone of 3cm to 30cm gamut and is being oriented to overlapping One in range subset 3-9cm, 6-12cm, 9-15cm, 12-18cm, 15-21cm, 18-24cm, 21-27cm and 24-30cm Single-tone between alternately.For example, at first of scan pattern during 12 seconds, each guiding in single-tone t1-t2, t5-t6 etc. Gamut, and single-tone t3-t4, t7-t8 etc. are then oriented to 3cm to 9cm range subset.Then it is single during next 12 seconds Each guiding gamut in sound t1-t2, t5-t6 etc., and single-tone t3-t4, t7-t8 etc. are then oriented to 6-12cm scope Collection.Finally, during last 12 seconds of scan pattern, each guiding gamut in single-tone t1-t2, t5-t6 etc., and Single-tone t3-t4, t7-t8 etc. are then oriented to 24-30cm range subset.

As shown as the demodulation tone signal line DETQ 602 in Fig. 9 A, and pass through control signal wire CH1 (demodulator 532 is alternately connected to process circuit (or SW, if real in SW to 604 and CH2 606 by it by switch 534 If existing front end) passage 1 or passage 2 in any one on) show as, transducer 524 is in a similar way alternately Receives echo-signal.For example, at first of scan pattern during 12 seconds, transducer 524 receives in interval r1-r2, r5-r6 Echo-signal from gamut, and the echo letter of the range subset from 3-9cm is received in interval r3-r4, r7-r8 etc. Number.Then in scanning-mode it one during 12 seconds, transducer 524 receives in interval r1-r2, r5-r6 etc. and comes from whole model The echo-signal enclosed, and the echo-signal of the range subset from 6-12cm is received in interval r3-r4, r7-r8 etc..Finally, During last 12 seconds of scan pattern, transducer 524 is received from gamut in interval r1-r2, r5-r6 etc. Echo-signal, and the echo-signal of the range subset from 24-30cm is received in interval r3-r4, r7-r8 etc..Receive Echo-signal is exaggerated device 530 and amplified, and is demodulated device 532 and demodulates.Such as by the line 604 of passage 1 and the line of passage 2 in Fig. 9 A As 606 show, such echo-signal received is processed in passage 1 and passage 2, wherein, the processing of passage 1 is oriented to The echo-signal of gamut, and the processing guiding of passage 2 overlapping range (3-9cm, 6-12cm etc., wherein, scope is cyclically (for example, each circulation have 12 second duration) changes) echo-signal.

Signal transacting is cyclically subjected to by range subset respectively to be transmitted through each signal of passage 1 and 2.Showing Example implementation in, each signal is transmitted through passage 1, and corresponding to by sampling and the storage of holding capacitor device (keeping 1) 536 And the entire depth scope filtered by bandpass filter 538 (wave filter 1).In the illustrated example, bandpass filter 1 filters out Signal with the frequency less than 100Hz and higher than 300Hz, to remove extraneous noise.As indicated as arrow 576, this A little filtered signals are sent to multiplexer 540, and are exaggerated device 542 and amplify, audible to be obtained by loudspeaker 544 Output.As indicated as arrow 577, these filtered signals directly pass through single heart of fetus pattern passage (FHPch) analog-digital converter 550 is sent to, to be subsequently sent to heart of fetus pattern detector 568.

As the further instruction of arrow 578, filtered signal further passes through automatic gain controller 1 (546), automatic gain controller 1 (546) provides such signal stable amplitude, so as to eliminate changeability.Such After the envelope detected of signal experience envelope detector 1 (548), such signal is sent to analog-digital converter 550, to enter behavior The numeral conversion that the back-end digital component part of heart of fetus monitoring system 520 uses.As mentioned above, in some realities In existing, such simulation component can be replaced by numeric components part or software.

It is transmitted through passage 2 and the signal corresponding to the depth bounds subset cycled through is subjected to signal in a similar way Processing.Specifically, such signal of passage 2 is transmitted through by sampling and the storage of holding capacitor device 2 (keeping 2) 536, and Filtered by bandpass filter 538 (wave filter 2).In the illustrated example, bandpass filter 2 filter out with less than 100Hz and The signal of frequency higher than 300Hz, to remove extraneous noise.As indicated as arrow 584, these filtered signals are straight Connected single signal-quality detector passage (SQDch) and be sent to analog-digital converter 550, to be subsequently sent to signal matter Amount detector 2 (558).

As the further instruction of arrow 586, filtered signal 2 further passes through automatic gain controller 2 (546), automatic gain controller 2 (546) provides such signal stable amplitude, so as to eliminate changeability.Such Signal is subjected to after the envelope detected of envelope detector 2 (548), and such signal is sent to analog-digital converter 550, to enter behavior The numeral conversion that the back-end digital component part of heart of fetus monitoring system 520 uses.As mentioned above, in some realities In existing, the function of this simulation component part alternately performs, or is performed by software or numeric components part.

As shown and as indicating the line 664 in Fig. 9 as Fig. 8 lower half, from fetal heart frequency passage 1 (FHR1ch) signal is sent to fetal heart frequency detector FHR1 (554) and SQD1 558 from analog-digital converter 550.Fetal heart frequency Detector FHR1 (554) detects fetal heart frequency from such signal, and the fetal heart frequency detected is output into display 556 and strip recorder 557, as indicated as the line 666 in Fig. 9.

Signal-quality detector 1 (558) detection signal quality.As indicated as arrow 588, the signal matter that detects Amount is sent to signal quality comparator 560, and signal quality comparator 560 is by comparing power and predetermined threshold value, to signal Power perform Real-Time Evaluation.Signal quality metrics are sent to display 556.As indicated as arrow 590, if signal (as determined by being worth relative to predetermined threshold value) of poor quality, loss of signal alarm is sent to multiplexer 540, thus send audible alarm using amplifier 542 and loudspeaker 544.As indicated as arrow 592, from FHR1 The signal of detector 554 is further transmitted to heartbeat consistency detector 562.

As indicated as arrow 596, the signal from wave filter 1538 is transmitted through heart of fetus pattern passage (FHPch) heart of fetus pattern detector 568, the heart of fetus pattern that heart of fetus pattern detector 568 will detect are reached It is stored in as benchmark FH patterns in memory 566.This benchmark FH patterns are used subsequently to determine that pattern is related.

As indicated as the line 668 in the arrow 598 and Fig. 9 in Fig. 8, the signal from wave filter 2538 sends and worn Cross signal quality sense channel (SQDch) arriving signal mass detector 2 (558), signal-quality detector 2 (558) measurement or The quality (intensity etc.) of signal as evaluation.The result of evaluation is sent to depth or area's selector 564 (is also referred to as used to select TD (timing diagram) selector of the depth bounds subset monitored for subsequent heart of fetus).

As indicated as the line 670 in the arrow 600 and Fig. 9 in Fig. 8, the signal from ED2548 is further sent The detector of fetal heart frequency 2 (554) is reached through the passage of fetal heart frequency 2 (FHR2ch).The detector of fetal heart frequency 2 (554) detection is each The fetal heart frequency of individual specific depth sub-range or subset.As indicated as the line 674 in Fig. 9, the fetus heart that detects Rate is sent to：(1) signal-quality detector 2 (558), for evaluating the signal matter from specific depth bounds or subset Amount；And (2) HBC detectors 562, for consistent between the heart rate in the fetal heart frequency and passage 2 in evaluation passage 1 Property.

As indicated as the line 672 in Fig. 9, signal-quality detector 2 evaluates signal quality.In one example, Signal-quality detector 2 makees following evaluate to signal quality：

1) the power SPx of the section of the signal on SQDch is evaluated.Section is directed at section HR2_x (for specific depth model Defensive wall collection and the fetal heart frequency detected)

2) SQD2_x=SPx*g (TDx), wherein x=39,612,915,1218,1521,1824,2127,2430 (39 are 3cm to 9cm abbreviation, 612 be 6cm to 12cm abbreviation etc.), and g (TDx) is limited by following table 1 to compensate acoustic attenuation.

Table 1

In another realization, signal-quality detector 2 (558) makees following evaluate to signal quality：

1) y [i]=absolute_value (F2_x [i]), i=0 ... I-1

Wherein：

A) x=39,612,915,1218,1521,1824,2127,2430

B) I=10 [s] * Fs

C) Fs-ADC sampling rate (for example, 1ksps)

D) 10 [s]-section F2_x length

2) z [i]=sum (y [i+j], j=0 ... 89)/90, i=0 ... I-1-89

3) Zmax=max (z [i], i=0 ... I-90)

4) z [i]=0for i=Imax-BI, Imax-BI+1 ..., Imax, Imax+1 ..., Imax+BI-1, Imax+BI

Wherein：

A) index of the element Zmax in Imax- vectors z []

B) BI=integer (60000/ (HR2_x_mean+2*HR2_x_std))

C) HR2_x_mean=mean (HR2_x [j], j=0 ... 40-1)

D) 40 [sample]=10 [s] * 4 [samples/sec]

E) 10 [s]-section HR2_x length

F) 4 [samples/secs]-traditional FHR exports sampling rate

G) HR2_x_std=standard_deviation (HR2_x [j], j=0 ... 40-1)

5) Zmax is put into Zmax_vector

If 6) for any i=0 ... I-90 z [i]=0, then step 7 is gone to, otherwise goes to step 3

7) greatest member in vector Z max_vector is obtained, and is zero

8) Zmax_mean=mean (Zmax_vector)

9) SQD2_x=Zmax_mean*g (TDx), wherein, g () is limited in upper table.

As indicated as the line 674 in the arrow 604 and Fig. 9 in Fig. 8, the fetal heart frequency detected is further sent To heartbeat consistency detector 562.Heartbeat consistency detector 562 determines heart rate (its detected in entire depth scope Received from fetal heart frequency detector 1 (554), as indicated as arrow 592) and detected in each depth bounds subset Heart rate (its received from fetal heart frequency detector 2 (554), as indicated as arrow 604) between uniformity.At one In realization, each depth bounds is evaluated relative to the corresponding section for the signal for being transmitted through passage 1 (gamut scanning) Subset, be transmitted through the signal of passage 2.As indicated as the line 676 in Fig. 9, each depth bounds subset is examined The uniformity measured is sent to range selector 564.

According to a realization, the uniformity between the heart rate detected is defined below：

1) E [j]=sum (absolute_value (HR1_330_x [i+j]-HR2_x [i]), i=0 ... 40-1), j= 0…8

Wherein：

A) x=39,612,915,1218,1521,1824,2127,2430

B) HR1_330_x [i], i=0 ... 48-1

C) 48 [sample]=12 [s] * 4 [samples/sec]

D) 12 [s]-section HR1_330_x length

E) 4 [samples/sec]-FHR export sampling rate

F) HR2_x [i], i=0 ... 40-1

G) 40 [sample]=10 [s] * 4 [samples/sec]

H) 10 [s]-section HR2_x length

I) section HR1_330_x and HR2_x such as " control flow chart：Alignment as being shown in detailed scan pattern "

2) (E [j], j=0 ... is 8) by Emin=min

If 3) Emin ＜ threshold values, HBCx=1, otherwise HBCx=0.

Once depth bounds selector 564 (TD selectors) is received to come from heartbeat consistency detector 562 and signal All information of mass detector 558, range selector 564 just identify those using signal conformance and intensity or signal quality Adjacent region.The border of such adjacent region and overlapping region is used for limiting all tires described as mentioned above for step 206 and Fig. 4 Youngster's cardiac window 152.For the selected belly depth that monitors heart of fetus scope or be ready to use in the window of monitoring heart of fetus Mouth is stored in memory 566.

According to an example implementation, selector 564 selects a pair of adjacent depth areas as described below：

1) Xmax1=get_x_of_max_element (SQD2_x*HBCx, x=39,612,915,1218,1521, 1824,2127,2430)

2) Xmax2=get_x_of_max_element (SQD2_x*HBCx, x=39,612,915,1218,1521, 1824,2127,2430, exclude x=Xmaxl)

3) Tdy is selected according to table 2.

Table 2

As shown as Fig. 7, once identified heart of fetus window 152 (TDx) (figure 3 illustrates), can open Beginning continuously monitors heart of fetus, and heart of fetus monitoring system 520 is entered in monitoring pattern MM.Figure 10 is schematically shown Heart of fetus monitoring system 520, the component that is used during monitoring pattern MM.As shown as Figure 10, in monitoring mould During formula, heart of fetus monitoring system 520 uses heart of fetus pattern comparator 620 in addition.In operation, Digital Logic 526 Produce and concentrate on ultrasound transmission tone signal on the window 152 of selection, being exaggerated the amplification of device 528.

Figure 10 A are the sequential for an example for showing this ultrasonic penetration scope during this heart of fetus monitors Figure and its associated time-scale.As shown as Figure 10 A, Digital Logic 526 and amplifier 528 make transmission tone signal 682 are launched by transducer 524, wherein, such embedded heart of fetus window or model for sending the guided selection of tone signal 682 Enclose.As shown as the line 682 in Figure 10 A, when system 520 is in monitoring pattern, single-tone t1-t4, t3-t4, t5-t6 Deng the scope of the selection of pilot notched 152.The receives echo-signal in a similar way of transducer 524.As that shown in line 684 Sample, transducer 524 receive the echo-signal of the scope from selection in interval r1-r2, r3-r4 etc..The echo letter received Number exaggerated device 530 amplifies, and is demodulated device 532 and demodulates.As shown as CH11 lines 686, the echo received is believed Number it is processed in the channel 1.As shown as CH1 lines 688, during monitoring pattern, signal is not transmitted through passage 2.

As shown as Fig. 8, before the low portion evaluation for the system 520 being shown in FIG. 10, such prison Survey signal and be subjected to other signal transacting.As shown in Figure 10 upper part, such monitoring signals by sampling and Holding capacitor device keeps 1 (536) storage, and is filtered by bandpass filter 1 (538).As indicated as arrow 626, warp The signal of filtering is sent to multiplexer 540, is exaggerated device 542 and amplifies, and is exported by loudspeaker 544.Such as by arrow 628 As instruction, filtered signal is further directly transmitted through heart of fetus pattern passage (FHPch), directly reaches modulus Converter 550 and heart of fetus pattern detector 568.Analog-digital converter is being sent to across the passage of fetal heart frequency 1 (FHR1ch) Before 550, filtered signal along the passage of fetal heart frequency 1 (FHR1ch) be further transmitted to automatic growth control 1 (546) and Envelope detector 1 (548).In other realizations, the one or more of the simulation component shown can be by numeric components or by one Or the software that multiple processors are realized replaces.

As lower half such as Figure 10 is shown, the data signal based on the ultrasound echo signal monitored is sent to FHR1 Detector (554), FHR1 detectors (554) detection fetal heart frequency, and send its output to display 556 and recorder 557.The data signal sent along heart of fetus pattern passage (FHPch) is sent to heart of fetus pattern detector 568, fetus Current heart of fetus pattern is output to heart of fetus pattern comparator 620 by heart pattern detector 568.Such as referred to by arrow 632 As showing, heart of fetus pattern comparator is further using the benchmark heart of fetus pattern being stored in memory 566 as defeated Enter.Heart of fetus pattern comparator 620 compares the current heart of fetus pattern and the benchmark fetus heart of monitoring signals for for example every 1 minute Dirty pattern is once.

In one implementation, in order to determine the pattern of monitoring signals whether fully correspond to reference signal pattern, tire Youngster's heart pattern comparator 620 evaluates the comparison of the matching threshold of the advance restriction with being stored in memory 566.Threshold value has The value of selection so that threshold value it is sufficiently low and even if one group of monitored ultrasound echo signal is merely due to heart of fetus angular orientation changes And change and be also exceeded, so as to avoid false alarm.Meanwhile threshold value has sufficiently high value, to surpass at monitored one group Sound echo-signal deteriorates or due to making transducer 24 undesirably be locked in unnecessary mother's belly due to fetal stress The influence of mother on vascular or fetus movement and be not exceeded when changing.

In one example, the average amplitude spectrum of fetal heartbeat is used as the pattern of reference signal, benchmark signal Pattern and monitoring signals.In one implementation, coefficient correlation is used as to the degree of the similitude between monitoring signals and reference signal Amount.In one example, average amplitude spectrum was obtained from monitoring signals with 2ksps sampling rate with the interval of every 10 seconds.Phase Relation number is Pearson correlation coefficients.As indicated as arrow 630, if coefficient is less than threshold value, alarm signal is sent out Multiplexer 540 is given, wherein, alarm signal is exaggerated device 542 and amplified, and is exported by loudspeaker 544, is looked after with reminding Person pays attention to losing fetal cardiac signals, and may be locked on mother's belly vascular.As indicated as arrow 642, Alarm signal is further transmitted to display 556, so as to further visually notify tender.In other examples, it can make With other patterns, other sampling rates and other coefficient correlations come make between reference signal and monitoring signals correlation or Match somebody with somebody.As shown as Fig. 7, the healthy calm of fetus is determined after alarm exports at the time 690, and in tender After danger, tender can adjust the positioning of transducer 524, to recover the reliable monitoring to heart of fetus.Specifically, tender Transducer positioning search pattern (TPS) is restarted again, so as to repeat to be initially positioned at for the first time on belly in transducer When and the step of same as described above.Once transducer 524 has been located at tender can be visually and acoustically true Determine the opening position that peak signal is just being received by transducer 524, tender can be by the input instruction of keyboard 570, so as to interrupt TPS moulds Formula.Therefore, or it is automatically, or in response to the order that tender is inputted using keyboard 570, scan schedule device 572 makes the monitoring be System 520 again goes into scan pattern SM (showing in figures 7 and 9).Scan pattern performs as described above, until Chosen desired window or scope 152 are come untill further being monitored.Once having identified window, restart In monitoring pattern MM heart of fetus is monitored using window.Monitor, export alarm, reposition transducer, re-recognize tire Youngster's cardiac window and heart of fetus is monitored again using the heart of fetus window identified recently, this circulates in system It is repeated continuously during 520 monitoring heart of fetus.

Figure 11 is the control flow chart for showing the exemplary method 700 for monitoring single fetus.Method 700 is similar to side Method 400 (figure 7 illustrates), simply method 700 using the elimination pattern 110 (figure 2 illustrates) being generally described detect sense The influence of mother's pulse measured.Figure 12 schematically show fetal monitoring system 520, during heart of fetus is monitored For this alternative those part for eliminating pattern 110.Fetal monitoring system 520 is configured to perform fetus pattern correlation wherein Pattern 108 or fetal signals are eliminated in other realizations of the only one in pattern 110, can be omitted in Fig. 8,10 and 12 and be shown , those components being not used in single pattern.For example, in wherein the realization of elimination pattern is only provided, the fetus heart can be omitted Dirty pattern detector 568, the memory 566 for Memory Reference pattern.Heart of fetus pattern comparator 620 is by mother's belly arteries and veins (MAV) signal detector is managed to replace.

As shown as Figure 11, in method 700, tender with above for identical described by method 400 Mode position transducer 524.Equally, in method 700, by with above for knowing in a manner of the identical described by method 400 Other heart of fetus window 152.But with method 400 on the contrary, once identified or selection heart of fetus window 152, such as by scheming As line 702 in 11 indicates, be carried out mother's belly vessel detection, with determine transducer 524 when whether prelocalization can Produce by the window 152 of mother's pulse or effect of signals caused by mother's belly vascular (MAV).

As shown as Figure 12, during this mother's belly vessel detection, Digital Logic 526 produces and concentrates on choosing Ultrasound on the window 152 selected sends tone signal, and ultrasound sends the exaggerated device 528 of tone signal and amplified.From window 152 Reflection echo signal is then received by transducer 524, and is exaggerated device 530 and is amplified.Such signal is further demodulated device 532 demodulation, and passage 1 (534) is transmitted through, to carry out further signal transacting.Specifically, such monitoring signals By sampling and holding capacitor device 1 (keeping 1) (536) storage, and filtered by bandpass filter 1 (538).Such as referred to by arrow 826 As showing, filtered signal is sent to multiplexer 540, is exaggerated device 542 and amplifies, and is exported by loudspeaker 544. Before analog-digital converter 550 is sent to through the passage of fetal heart frequency 1 (FHR1ch), filtered signal is along fetal heart frequency 1 Passage (FHR1ch) is further transmitted to automatic growth control 1 (546) and envelope detector 1 (548).In other realizations, show One or more of simulation component gone out can be by the realization by one or more processors numeric components or software generation Replace.

As shown in Figure 12 lower half, the data signal based on the ultrasound echo signal monitored is sent to tire The detector of youngster's heart rate 1 (554), the detector of fetal heart frequency 1 (554) detection fetal heart frequency, and send its output to display 556 and recorder 557.As indicated as arrow 828, fetal heart rate signal is further transmitted to signal-quality detector 1 And MAV detectors 860 (558).Signal-quality detector 1 (558) detection signal quality.The signal quality detected is sent to letter Number quality comparator 560, signal quality comparator 560 are held by comparing power with predetermined threshold value to the power of signal Row Real-Time Evaluation.Signal quality metrics are sent to display 556.As indicated as arrow 890, if single of poor quality (as determined by being worth relative to predetermined threshold value), loss of signal alarm is sent to multiplexer 540, thus Audible alarm is sent using amplifier 542 and loudspeaker 544.

Figure 13 schematically shows MAV detectors 860 in further detail.As shown as Figure 13, MAV detectors 860 include heart rate detector 900, cancellation module 902, residual signal heart rate detector 903, heartbeat consistency detector 904 and alarm generator 906.MAV detectors 860 are supervised in the period (in the illustrated example, 10 seconds) limited in advance inner receive Survey the sample of signal.This signal is sent to cancellation module 902 and heart rate detector 900.HR detectors 900 do not add from such Heart rate is detected in the signal of work, and output heart rate HR is sent to heartbeat consistency detector 904.

Cancellation module 902 performs removing method 300 (figure 5 illustrates).Specifically, as indicated as frame 912, Fetal signals cancellation module 902 performs the frame 302-312 shown on Fig. 5, to obtain the normalization pattern 1M of fetal signals.Such as by As frame 914 indicates, module 902 performs the frame 314 shown on Fig. 5, and composite signal is obtained afterwards to be eliminated in fetal signals S1 (is referred to as residual signal).Residual signal S1 is sent to residual signal heart rate detector 903, residual signal heart rate detector 903 The heart beat rate HR1 of residual signal presence is determined, and heart rate HR1 is sent to heartbeat consistency detector 904.The heart Jump consistency detector 904 and evaluate the degree of consistency or water between heart rate HR1 and heart rate HR received from heart rate detector 900 It is flat.As indicated in Figure 13, if fetal heart frequency HR1 exists and is unsatisfactory for limiting in advance consistent with fetal heart frequency HR Property degree, then MAV alarm generators 906 produce alarm.In one implementation, in order to meet the degree of consistency limited in advance, Difference between HR and HR1 is necessarily less than the threshold value of five heartbeats per minute.In other realizations, other threshold values can be used.Such as As indicating the arrow 894 in Figure 12, alarm signal is sent to multiplexer 540, wherein, alarm signal is exaggerated device 542 amplifications, and exported by loudspeaker 544.Alternatively, if heart rate HR1 is not present, or be unsatisfactory for limiting in advance and HR The degree of consistency, then do not detect mother's signal, and alarm does not ring.Figure 11 illustrates sample situation in, transducer 524 Initial alignment can cause MAV alarms of sounding, as indicated as step 706.Therefore, tender restarts transducer position Search pattern is put, and repositions transducer.As step 708 and 710 instructions, also performed scan pattern, so as to New HR windows 152 are identified in the new position of transducer 524.As indicated as step 712, perform explain above again The MAV detections stated.But in this case, no MAV alarms are sounded.Afterwards, continue to monitor fetal heart frequency.What is shown In sample situation, as indicated at point 714, alarm is sounded (by signal quality comparator again due to the loss of signal The low signal quality (figure 12 illustrates) of 560 identifications).Therefore, operator starts transducer position search pattern again, and And reposition transducer 524.Due to this repositioning of transducer 524, as indicated as step 716, again Scan pattern is performed, to identify heart of fetus window 152, heart of fetus window 152 can be new, or can be with window before As 152.Due to this repositioning, MAV detections are repeated.If MAV detections produce the MAV alarms of positive output, shield is prompted Scholar repositions transducer 542 again, so as to the start-up course at step 706.

Although describing the disclosure with reference to example embodiment, it will be recognized to those skilled in the art that can be not Change is made in terms of form and details in the case of the spirit and scope for deviateing claimed theme.Although for example, It is described as including providing different example embodiments to one or more features of one or more benefits, but it is contemplated that, Described feature can be with interchangeable with one another, either alternatively in the example embodiment of description or in other alternatives With being bonded to each other.Because the technology of the disclosure is more complicated, so not being that all changes in technology are all foreseeable.Reference is shown Example embodiment is obviously intended to wide in range as much as possible come the disclosure that is describing and illustrating in the following claims.For example, unless Especially it is otherwise noted, otherwise describes the claim of single specific factor also comprising multiple such specific factors.

Claims

1. a kind of heart of fetus monitoring method, including：

The ultrasonic signal from heart of fetus is obtained from ultrasonic transducer；

Contributed by suppressing any mother from ultrasound echo signal to determine the fetal cardiac signals to the ultrasonic signal Contribution, wherein, the fetal cardiac signals contribution is point of the ultrasonic Doppler echo-signal as caused by the pulsation of heart of fetus Amount, and wherein, mother's contribution is point of the ultrasonic Doppler echo-signal as caused by the pulsation of the blood in mother's abdominal muscles Amount；

The fetal cardiac signals contribution is eliminated from the ultrasonic signal, wherein, based on the result of the elimination, output police Report.

2. heart of fetus monitoring method according to claim 1, methods described further comprise：

It is determined that the presence of the first heart rate detected on any residual signal after the elimination；And

First heart rate and the uniformity of the second heart rate detected on the ultrasonic signal are evaluated, wherein, if described First heart rate is present, and is unsatisfactory for the predetermined degree of consistency with second heart rate, then exports alarm.

3. heart of fetus monitoring method according to claim 1, wherein, the ultrasonic signal is obtained in the following manner：

Determine the approximate distance between ultrasonic transducer and the heart of fetus；And

Using the ultrasonic transducer, sensing and the scope of the distance of the ultrasonic transducer, the scope have based on described The minimum range of approximate distance.

4. heart of fetus monitoring method according to claim 3, wherein, the scope has based on the approximate distance Ultimate range.

5. heart of fetus monitoring method according to claim 4, wherein, the minimum range of the scope with it is described near Spacing is separated like distance.

6. heart of fetus monitoring method according to claim 4, wherein, the minimum range of the scope and the model The ultimate range enclosed forms the window closed the heart of fetus and separated with the heart of fetus.

7. heart of fetus monitoring method according to claim 4, wherein it is determined that the approximate distance includes sensing overlapping depth Area is spent, wherein, the lap in the adjacent depth area of highest two here of the intensity based on echo-signal is described near to determine Like distance.

8. heart of fetus monitoring method according to claim 7, methods described further comprises being based on from multipair adjacent depth Each ultrasonic signal to reflection in degree area handle obtained by heart rate with from the whole of all multipair adjacent depth areas Scope reflection ultrasonic signal handled obtained by fetal heart frequency uniformity, select described two from multipair adjacent depth area Individual adjacent depth area.

9. heart of fetus monitoring method according to claim 1, wherein it is determined that believing the heart of fetus of the ultrasonic signal Number contribution and heart of fetus contribution is eliminated from the ultrasonic signal include：

Auto-correlation is carried out to the ultrasonic signal；

Obtain the cycle between the first fetal heartbeat；

Identify the minimum value in the cycle；

The section of the ultrasonic signal is cut off, wherein, each section has the length corresponding to the minimum value, and is directed at institute State the first fetal heartbeat；

By the amplitude of first fetal heartbeat in the section, each section is set to standardize；

Determine the average value of the normalization section；And

Normalized average mean segment is subtracted from each section.

10. a kind of heart of fetus monitoring system, including：

Ultrasonic transducer；

Controller, it is configured to produce the operation for guiding the ultrasonic transducer and receives returning from the ultrasonic transducer The control signal of ripple signal, the controller are configured to：

The ultrasonic signal from heart of fetus is obtained from ultrasonic transducer；And

Contributed by suppressing any mother from the ultrasonic signal to determine the fetal cardiac signals to the ultrasonic signal Contribution, wherein, the fetal cardiac signals contribution is point of the ultrasonic Doppler echo-signal as caused by the pulsation of heart of fetus Amount, and wherein, mother's contribution is point of the ultrasonic Doppler echo-signal as caused by the pulsation of the blood in mother's abdominal muscles Amount；And

11. heart of fetus monitoring system according to claim 10, wherein, the controller is configured to：

It is determined that the presence of the residual signal after the elimination；And

The uniformity of the heart rate of any residual signal and the fetal heart frequency of the ultrasonic signal is evaluated, wherein, if the residue Signal is present, and inconsistent with the fetal heart frequency of the ultrasonic signal, then exports alarm.

12. heart of fetus monitoring system according to claim 10, wherein, referenced ultrasound echo is obtained in the following manner Signal：

The scope with the distance of the ultrasonic transducer is sensed using the ultrasonic transducer, the scope has based on described The minimum range of approximate distance.

13. heart of fetus monitoring system according to claim 10, wherein, the controller is configured in the following manner Suppress described mother contribution from the ultrasonic signal：

Auto-correlation is carried out to the ultrasonic signal；

Obtain the cycle between the first fetal heartbeat；

Identify the minimum value in the cycle；

Determine the average value of the normalization section；And

Normalized average mean segment is subtracted from each section.

14. a kind of medical apparatus, including：

For obtaining the device of the ultrasonic signal from heart of fetus from ultrasonic transducer；

For being contributed by suppressing any mother from ultrasonic signal, it is determined that the fetal cardiac signals tribute to the ultrasonic signal The device offered, wherein, the fetal cardiac signals contribution is the ultrasonic Doppler echo-signal as caused by the pulsation of heart of fetus Component, and wherein, mother's contribution is the ultrasonic Doppler echo-signal as caused by the pulsation of the blood in mother's abdominal muscles Component；And

For eliminating the device of the fetal cardiac signals contribution from the ultrasonic signal；And

For the result based on the elimination, the device of alarm is exported.

15. device according to claim 14, in addition to：

For the existing device for the first heart rate for determining to detect on any residual signal after the elimination；And

For evaluating first heart rate and the device of the uniformity of the second heart rate detected on the ultrasonic signal,

If for determining that first heart rate is present, and it is unsatisfactory for the predetermined uniformity journey with second heart rate Degree, then export the device of alarm.

16. device according to claim 14, in addition to：

For determining the device of the approximate distance between ultrasonic transducer and the heart of fetus；

For sensing the device with the scope of the distance of the ultrasonic transducer, the scope tool using the ultrasonic transducer There is the minimum range based on the approximate distance；And

For using the ultrasound echo signal from the scope, the device of the heart rate of the heart of fetus is monitored.

17. device according to claim 16, in addition to：

The device of the approximate distance is determined by sensing overlapping depth area for bootstrap processor,

Lap for the highest two adjacent depth area here of the intensity based on echo-signal determines the approximation Distance.

18. device according to claim 17, in addition to：

For guiding the processor to be obtained based on being handled from each ultrasonic signal to reflection in multipair adjacent depth area Heart rate handled with the ultrasonic signal reflected from the gamut in all multipair adjacent depth areas obtained by the fetus heart The uniformity of rate, the device in described two adjacent depth areas is selected from multipair adjacent depth area.

19. device according to claim 14, in addition to：

Eliminate the device of the fetal cardiac signals contribution from the ultrasonic signal in the following manner for bootstrap processor：

Auto-correlation is carried out to the ultrasonic signal；

Obtain the cycle between the first fetal heartbeat；

Identify the minimum value in the cycle；

Determine the average value of the normalization section；And

Normalized average mean segment is subtracted from each section.

20. device according to claim 14, in addition to：

Window for bootstrap processor identification around the heart of fetus, and obtain be only from it is described super in the window The device of acoustical signal.